A magnetic random access memory (MRAM) element having a magnetic tunnel junction (MTJ) structure has attracted attention as one type of a memory element using a magnetoresistance effect element.
The MRAM element includes a multilayered film formed from a hard-to-etch material which contains a metal such as a ferromagnetic substance. In manufacturing of such an MRAM element, for example, a platinum manganese (PtMn) layer is etched by using a mask containing tantalum (Ta). In such etching, a halogen gas has been conventionally used, as disclosed in Japanese Patent Application Laid-Open Publication No. 2012-204408.